Led lamp

ABSTRACT

An exemplary embodiment of the present invention relates to a light-emitting diode (LED) lamp including a first light-emitting unit and a second light-emitting unit arranged above and below a reflector, so that light is emitted in both an upwards and downwards direction and light is reflected by the reflector, and so that the LED lamp has light distribution characteristics similar to those of conventional filament lamps.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority from and the benefit of Korean PatentApplication No. 10-2011-0042947, filed on May 6, 2011, which is herebyincorporated by reference for all purposes as if fully set forth herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Exemplary embodiments of the present invention relate generally tolight-emitting diode (LED) lamps and, more particularly, to an LED lampin which a first light emitting unit and a second light emitting unitare disposed above and below a reflector so that light is emittedupwards and downwards and light is reflected by the reflector, thusforming light distribution characteristics similar to that ofconventional filament lamps.

2. Discussion of the Background

Lamps may be used for chandeliers, decoration lighting, etc. Lamps usingconventional filament light bulbs have been widely used in theseapplications. However, conventional filament light bulbs may have ashort lifetime, forcing users to frequently replace them with new ones.

In part to overcome the problems of conventional filament light bulbs,LED lamps were developed, which may have low power consumption and along lifetime. However, in the case of conventional LED lamps, becauseof size limitations, the size of a heat sink in the LED lamp may belimited. Therefore, it may be difficult to effectively dissipate heatgenerated from LED lamps when emitting light.

Moreover, characteristics of LED lamps in which light emitted therefromonly travels in a forward direction may make it difficult to form lightdistribution patterns similar to those of convention filament lightbulbs that emit light in all directions. Therefore, substituting LEDlamps for filament lamps has been limited.

The above information disclosed in this Background section is only forenhancement of understanding of the background of the invention andtherefore it may contain information that does not form any part of theprior art nor what the prior art may suggest to a person of ordinaryskill in the art.

SUMMARY OF THE INVENTION

Exemplary embodiments of the present invention provide an LED lamp inwhich a first light emitting unit and a second light emitting unit aredisposed above and below a reflector so that light is emitted upwardsand downwards and light is reflected by the reflector, thus forminglight distribution characteristics similar to those of conventionalfilament lamps.

Exemplary embodiments of the present invention also provide an LED lampwhich separately has a first heat sink and a second heat sink so thatheat generated from the first light emitting unit and heat generatedfrom the second light emitting unit can be independently dissipated,thus enhancing the heat dissipation efficiency of the LED lamp.

Additional features of the invention will be set forth in thedescription which follows, and in part will be apparent from thedescription, or may be learned by practice of the invention.

An exemplary embodiment of the present invention provides alight-emitting diode LED lamp, including a base unit having a connectionpart arranged at a first end thereof, the connection part configured toreceive external power, a first light-emitting unit including a firstcircuit board arranged on a second end of the base unit, and at leastone first LED mounted on the first circuit board, a secondlight-emitting unit including a second circuit board spaced apart fromthe first circuit board, and at least one second LED mounted on thesecond circuit board, the second LED facing the first LED, a reflectorarranged between the first circuit board and the second circuit board,the reflector configured to reflect light emitted from the first LED andthe second LED, and a transparent cover surrounding the firstlight-emitting unit, the second light-emitting unit, and the reflector,wherein the transparent cover is configured to protect the firstlight-emitting unit, the second light-emitting unit, and the reflectorfrom exposure to an outside environment.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention, andtogether with the description serve to explain the principles of theinvention.

FIG. 1 is a perspective view illustrating an LED lamp, according to anexemplary embodiment of the present invention.

FIG. 2 is an exploded perspective view of the LED lamp of FIG. 1.

FIG. 3 is a cross-sectional view of the assembled LED lamp of FIG. 1.

FIG. 4 is a view showing paths along which rays of light are emittedfrom the LED lamp according to the exemplary embodiment of FIG. 1.

FIG. 5 shows a variety of shapes of a reflector used in the exemplaryembodiment shown in FIG. 1.

FIG. 6 a, FIG. 6 b, and FIG. 6 c are views showing several examples of amethod of coupling of a reflector to circuit boards according to theexemplary embodiment shown in FIG. 1.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

The invention is described more fully hereinafter with reference to theaccompanying drawings, in which exemplary embodiments of the inventionare shown. This invention may, however, be embodied in many differentforms and should not be construed as limited to the exemplaryembodiments set forth herein. Rather, these exemplary embodiments areprovided so that this disclosure is thorough, and will fully convey thescope of the invention to those skilled in the art. In the drawings, thesize and relative sizes of layers and regions may be exaggerated forclarity. Like reference numerals in the drawings denote like elements.

It will be understood that when an element or layer is referred to asbeing “on” or “connected to” another element or layer, it can bedirectly on or directly connected to the other element or layer, orintervening elements or layers may be present. In contrast, when anelement is referred to as being “directly on” or “directly connected to”another element or layer, there are no intervening elements or layerspresent. It will be understood that for the purposes of this disclosure,“at least one of X, Y, and Z” can be construed as X only, Y only, Zonly, or any combination of two or more items X, Y, and Z (e.g., XYZ,XYY, YZ, ZZ).

Spatially relative terms, such as “beneath”, “below”, “lower”, “above”,“upper” and the like, may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It will be understood that thespatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, elements described as “below” or “beneath” otherelements or features would then be oriented “above” the other elementsor features. Thus, the exemplary term “below” can encompass both anorientation of above and below. The device may be otherwise oriented(rotated 90 degrees or at other orientations) and the spatially relativedescriptors used herein interpreted accordingly.

An LED lamp 100 according to an exemplary embodiment of the presentinvention is characterized in that a first light emitting unit 130 and asecond light emitting unit 140 are respectively disposed below and abovea reflector 160 that has a first reflective surface 161 a and a secondreflective surface 162 a, so that rays of light emitted upwards anddownwards are reflected by the first reflective surface 161 a and thesecond reflective surface 162 a, thus exhibiting similar lightdistribution characteristics to those of the conventional filamentlamps.

The LED lamp 100 includes a base unit 110, the first light emitting unit130, the second light emitting unit 140, the reflector 160 and atransparent cover 170.

The base unit 110 forms a portion of the external appearance of the LEDlamp 100, and functions to receive external power and supply the powerto the first and second light emitting units 130 and 140 that includeLEDs.

In detail, as shown in FIG. 1, FIG. 2, and FIG. 3, a connection part 112is provided in a lower end of the base unit 110 so that external powercan be applied to the base unit 110 by the connection part 112. Theconnection part 112 has a shape corresponding to those of typicalsockets for incandescent lamps, thus enabling the LED lamp 100 to becoupled to the typical sockets. A converter 180 is installed in the baseunit 110 to convert power applied from the connection part 112 intodirect-current (DC) power suitable for the LEDs. A power cable (notshown) electrically connects the converter 180 to a first circuit board132 on which a first LED 134 is mounted, so that DC power can besupplied to the first circuit board 132.

The first light emitting unit 130 is disposed above the base unit 110and emits light upwards (based on the orientation in FIG. 1, FIG. 2, andFIG. 3) when power is applied thereto. In the first light emitting unit130, at least one first LED 134 is mounted on the first circuit board132 that is electrically connected to the converter 180. As shown inFIG. 4, rays of light emitted from the first LED 134 may travel straightto the transparent cover 170 and directly radiate out of the LED lamp100 or may be reflected by the reflector 160 before radiating out of theLED lamp 100 through the transparent cover 170.

The first light emitting unit 130 having the above-mentionedconstruction is mounted on a first heat sink 120 so that heat generatedwhen the first LED 134 emits light can be dissipated out of the LED lamp100. That is, as shown in FIG. 2 and FIG. 3, the first heat sink 120 iscoupled to the base unit 110, and a mounting surface 122 is formed on anupper surface of the first heat sink 120. The first circuit board 132comes into surface contact with the mounting surface 122. Thus, heatgenerated from the first LED 134 may be transferred to the first heatsink 120 via the first circuit board 132 and then dissipated to theoutside. Here, a plurality of heat dissipation fins 124 are provided ona circumferential outer surface of the first heat sink 120, thus furtherincreasing the heat dissipation effect.

The first circuit board 132 may be mounted on the mounting surface 122by an adhesive layer, such as heat dissipation tape or the like, or bydifferent kinds of coupling methods, for example, bolt coupling, screwcoupling, etc.

Although the first heat sink 120 has been illustrated as being providedas a separate element and coupled to the base unit 110 in the presentexemplary embodiment, the present invention is not limited to this. Forinstance, the base unit 110 and the first heat sink 120 may beconfigured such that they are integrally formed with each other, and themounting surface on which the first circuit board 132 is mounted isformed on the upper end of the base unit 110.

If the first heat sink 120 is integrally formed with the base unit 110,the base unit 110 may be made of a metal such as aluminum having highheat conductivity so that heat generated when the first light emittingunit 130 emits light can be effectively dissipated to the outside.Further, a plurality of heat dissipation fins may be provided on theouter surface of the base unit 110 to increase the heat dissipationsurface area, thus enhancing the heat dissipation efficiency.

The second light emitting unit 140 is disposed at a position spacedapart from the first light emitting unit 130 in the vertical directionby a predetermined distance. The second light emitting unit 140 emitslight in a direction opposite to the direction in which the first lightemitting unit 130 emits light. In other words, light emitted from thesecond light emitting unit 140 radiates downwards (based on theorientation in FIG. 1, FIG. 2, and FIG. 3).

In detail, the second light emitting unit 140 includes a second circuitboard 142 which is disposed at a position spaced upwards from the firstcircuit board 132 by a predetermined distance. At least one second LED144 is mounted on a lower surface of the second circuit board 142. Thatis, the second LED 144 is mounted on the second circuit board 142 thatfaces the first circuit board 132 in such a way that the second LED 144faces the first LED 134. Therefore, as shown in FIG. 4, some light L2emitted from the second LED 144 radiates behind the first LED 134 whilesome light L1 emitted from the first LED 134 radiates behind the secondLED 144, so that light emitted from the first and second light emittingunits 130 and 140 can radiate in all directions. Thereby, the overalllight distribution pattern of the LED lamp 100 of the present exemplaryembodiment may be similar to that of the conventional filament lamps.

The second light emitting unit 140 is mounted on a second heat sink 150so that heat generated when the second LED 144 emits light can bedissipated out of the LED lamp 100. In detail, as shown in FIG. 2 andFIG. 3, the second heat sink 150 is coupled to an upper end of thetransparent cover 170, and a mounting surface 152 is formed on a lowersurface of the second heat sink 150. The second circuit board 142 comesinto surface contact with the mounting surface 152. Thus, heat generatedfrom the second LED 144 is transferred to the second heat sink 150 viathe second circuit board 142 and then dissipated to the outside. Here, aplurality of heat dissipation fins 154 are provided on a circumferentialouter surface of the second heat sink 150, thus further increasing theheat dissipation effect.

As such, in the LED lamp 100 according to the present exemplaryembodiment, the first light emitting unit 130 and the second lightemitting unit 140 are respectively disposed below and above thereflector 160. Further, the LED lamp 100 includes the first heat sink120 and the second heat sink 150 so that heat generated from each of thefirst and second light emitting units 130 and 140 can be individuallydissipated. Therefore, the present exemplary embodiment maysatisfactorily dissipate heat generated from the LEDs, thus making itpossible to use not only a low power LED but also a high power LED as alight emitting source. Because the high power LED can be used as thelight emitting source, the LED lamp 100 can emit as sufficient intensityof light as the conventional filament lamps. As a result, the LED lamp100 may completely substitute for a conventional filament lamp.

The second circuit board 142 may also be mounted on the mounting surface152 by an adhesive layer, such as heat dissipation tape or the like, orby different kinds of coupling methods, for example, bolt coupling,screw coupling, etc., in the same manner as the first circuit board 132.

The second circuit board 142 that supplies power to the second LED 144is electrically connected to the first circuit board 132 or theconverter 180 by a power cable (not shown).

Each of the first LED 134 and the second LED 144 may be configured in ashape of a COB (Chip on Board) wherein a plurality of LED chips areintegrated on a board to form a light emitting chip, or may comprise apackage type of LED device including a lead frame, or may comprise acombination of the COB type and the LED device type. Light emitted fromeach LED may be at least one among red, blue, and green, or may be whitelight.

The reflector 160 reflects some light emitted from the first and secondLEDs 134 and 144 towards the transparent cover 170 in order to havedesired light distribution characteristics. The reflector 160 includes afirst reflective part 161 and a second reflective part 162 thatrespectively independently control light emitted from the first LED 134and light emitted from second LED 144. In detail, light emitted from thefirst LED 134 is reflected by the first reflective surface 161 a of thefirst reflective part 161 and bent towards the transparent cover 170,while light emitted from the second LED 144 is reflected by the secondreflective surface 162 a of the second reflective part 162 and benttowards the transparent cover 170.

Therefore, as shown in FIG. 4, in the LED lamp 100 according to thepresent exemplary embodiment, some light is emitted from the first LED134 forwards (that is, upwards) based on the first circuit board 132 anddirectly travels towards the transparent cover 170, and simultaneously,some light is reflected by the first reflective surface 161 a towardsthe transparent cover 170. In the same manner, some light is emittedfrom the second LED 144 forwards (that is, downwards) based on thesecond circuit board 142 and directly travels towards the transparentcover 170, and simultaneously, some light is reflected by the secondreflective surface 162 a towards the transparent cover 170.

As such, the LED lamp 100 according to the present exemplary embodimentis configured such that the first LED 134 and the second LED 144 faceeach other and are provided below and above the reflector 160, in otherwords, the reflector 160 is disposed between the first LED 134 and thesecond LED 144. Thus, substantially all light emitted from the first andsecond LEDs 134 and 144 may travel towards the transparent cover 170,thus making the overall light distribution pattern similar to that ofthe conventional filament lamps.

Moreover, thanks to the structure wherein the two light emitting sourcesare disposed above and below the reflector 160 and face each other,exemplary embodiments of the present invention can overcome thelimitations of LEDs that emit light straight and can radiate light evenbehind the light sources, thus forming a wide-angled light distributionpattern. Meanwhile, in the reflector 160 (including various exemplaryembodiments 160 a, 160 b, 160 c, 160 d, 160 e, 160 f, 160 g, 160 h, 160i, 160 j, and 160 k shown in FIG. 5) that reflects light emitted fromthe first and second LEDs 134 and 144 and sends it towards thetransparent cover 170, the shapes of the first and second reflectivesurfaces 161 a and 162 a can be modified in a variety of manners to havedesired light distribution patterns.

In detail, as shown in exemplary embodiment (a) of FIG. 5, the reflector160 may be configured such that the first reflective surface 161 a andthe second reflective surface 162 a are horizontally symmetrical to eachother based on a center or lateral line parallel to the first circuitboard 132. Further, the first reflective surface 161 a includes aninclined portion 163 that has a longitudinal cross-sectional shape whichis inclined from a lower end thereof to an upper end towards thetransparent cover 170, and a vertical portion 166 that extends apredetermined length upwards from the upper end of the inclined portion163.

As shown in exemplary embodiment (d) of FIG. 5, the reflector 160 may beconfigured such that the first reflective surface 161 a and the secondreflective surface 162 a are horizontally symmetrical to each otherbased on a center or lateral line parallel to the first circuit board132. Further, the first reflective surface 161 a includes a curvedportion 164 that has a longitudinal cross-sectional shape which iscurved from a lower end thereof to an upper end towards the transparentcover 170, and a vertical portion 166 that extends a predeterminedlength upwards from the upper end of the curved portion 164.

As shown in exemplary embodiment (h) of FIG. 5, the reflector 160 may beconfigured such that the first reflective surface 161 a and the secondreflective surface 162 a are horizontally symmetrical to each otherbased on a center or lateral line parallel to the first circuit board132. Further, the first reflective surface 161 a has a longitudinalcross-sectional shape that is curved from a lower end thereof to anupper end towards the transparent cover 170.

As shown in exemplary embodiment (i) of FIG. 5, the reflector 160 may beconfigured such that the first reflective surface 161 a and the secondreflective surface 162 a are horizontally symmetrical to each otherbased on a center or lateral line parallel to the first circuit board132. Further, the first reflective surface 161 a has a linearlongitudinal cross-sectional shape that is inclined from a lower endthereof to an upper end towards the transparent cover 170 at apredetermined angle.

Meanwhile, the first reflective part 161 and the second reflective part162 may s be configured such that the lengths thereof are different fromeach other (as shown in exemplary embodiments (b), (c), (e), (f) or (g)of FIG. 5).

In other words, the first reflective surface 161 a and the secondreflective surface 162 a may be configured such that they arehorizontally asymmetrical to each other based on a center or lateralline parallel to the first circuit board 132, while the length of thefirst reflective part 161 is greater or less than that of the secondreflective part 162.

As shown in exemplary embodiments (b) or (c) of FIG. 5, the reflector160 may be configured such that the first reflective surface 161 a has alinear longitudinal cross-sectional shape that is inclined from a lowerend thereof to an upper end towards the transparent cover 170 at apredetermined angle. Further, the second reflective surface 162 a has alinear longitudinal cross-sectional shape that is inclined from an upperend thereof to a lower end towards the transparent cover 170 at apredetermined angle.

As shown in exemplary embodiment (e) of FIG. 5, the reflector 160 may beconfigured such that the first reflective surface 161 a has alongitudinal cross-sectional shape which is curved from a lower endthereof to an upper end towards the transparent cover 170. Further, thesecond reflective surface 162 a has a linear longitudinalcross-sectional shape that is inclined from an upper end thereof to alower end towards the transparent cover 170 at a predetermined angle.

As shown in exemplary embodiment (g) of FIG. 5, the reflector 160 may beconfigured such that the first reflective surface 161 a has a linearlongitudinal cross-sectional shape that is inclined from a lower endthereof to an upper end towards the transparent cover 170 at apredetermined angle. Further, the second reflective surface 162 a has alongitudinal cross-sectional shape which is curved from an upper endthereof to a lower end towards the transparent cover 170.

As shown in exemplary embodiment (f) of FIG. 5, the reflector 160 may beconfigured such that the first reflective surface 161 a has alongitudinal cross-sectional shape which is curved from a lower endthereof to an upper end towards the transparent cover 170. Further, thesecond reflective surface 162 a has a longitudinal cross-sectional shapewhich is curved from an upper end thereof to a lower end towards thetransparent cover 170.

Although the first reflective surface 161 a and the second reflectivesurface 162 a are shown as smooth curves or inclines in thecircumferential direction in FIG. 5, they are not so limited and may befaceted or textured, for example.

Meanwhile, in the reflector 160 used in the LED lamp 100 of the presentexemplary embodiment, although the first reflective part 161 thatreflects light emitted from the first LED 134 may be integrally providedwith the second reflective part 162 that reflects light emitted from thesecond LED 144, as shown in exemplary embodiments (a), (b), (c), (d),(e), (f), (g), (h), and (i) of FIG. 5, the first reflective part 161 andthe second reflective part 162 may be separately formed and spaced apartfrom each other by a predetermined distance, as shown in exemplaryembodiments (j) and (k) of FIG. 5.

The material of the reflector 160 may be resin or metal. Further, areflective layer may be formed on an outer surface of the reflector 160,such as on an outer surface of each of the first and second reflectivesurfaces 161 a and 162 a, thus enhancing the efficiency of reflectinglight emitted from the light emitting sources.

Forming the reflective layer includes applying a material such asaluminum, chrome, etc., having high light reflectivity, to each of thefirst and second reflective surfaces 161 a and 162 a to a predetermineddepth. The reflective layer may be applied in various ways, for example,by deposition, anodizing, plating, etc.

The reflector 160 according to an exemplary embodiment of the presentinvention includes the first reflective part 161 that has the firstreflective surface 161 a and the second reflective part 162 that has thesecond reflective surface 162 a. Further, the reflector 160 is disposedbetween the first LED 134 and the second LED 144, and separatelycontrols the directions in which light emitted from the first LED 134and the second LED 144 is reflected by the reflector 160. The upper endof the reflector 160 is fastened to the second circuit board 142, andthe lower end thereof is fastened to the first circuit board 132.

In other words, the lower end of the first reflective part 161 isfastened to the first circuit board 132, while the upper end of thesecond reflective part 162 is fastened to the second circuit board 142.This structure is also applied in the case where, as shown in exemplaryembodiments (j) and (k) of FIG. 5, the first reflective part 161 and thesecond reflective part 162 are separated and spaced apart from eachother by a predetermined distance.

Fastening the reflector 160 to the first and second circuit boards 132and 142 may be realized in different ways, as shown in FIG. 6 a, FIG. 6b, and FIG. 6 c, which include several examples, including using aconnector member such as a hook, clip, pin, rivet, or adhesive.

In the exemplary embodiment shown in FIG. 6 a, at least one hook 167 isprovided on each of the upper and lower ends of the reflector 160. Thehooks 167 are inserted into corresponding locking holes 132 a and 142 a,which are respectively formed through the first and second circuitboards 132 and 142, and then hooked to the first and second circuitboards 132 and 142, thus fastening the upper and lower ends of thereflector 160 to the first and second circuit boards 132 and 142,respectively.

In the exemplary embodiment shown in FIG. 6 b, a coupling piece 168 isbent from each of upper and lower ends of the reflector 160 in onedirection. The coupling pieces 168 are fastened to the first and secondcircuit boards 132 and 142 by tightening fastening members 169 both intothe coupling pieces 168 and into fastening holes 132 b and 142 b formedin the first and second circuit boards 132 and 142.

Although each coupling piece 168 is illustrated in the present exemplaryembodiment as being bent outwards from the reflector 160, the presentinvention is not limited to this structure. For instance, the couplingpiece 168 may be bent from the reflector 160 inwards to reduceinterference with light emitted from the first and second LEDs 134 and144, thus enhancing the reflectivity of the reflector 160.

As shown in FIG. 6 c, the upper and lower ends of the reflector 160 maybe fastened to the first circuit board 132 and the second circuit board142 by an insulating adhesive. Here, grooves 132 c and 142 c may berespectively formed in the first circuit board 132 and the secondcircuit board 142 so that the upper and lower ends of the reflector 160can be inserted into the grooves 132 c and 142 c to predetermineddepths, thus enhancing the fastening force.

In the above-described exemplary embodiments, the locking holes 132 aand 142 a, the fastening holes 132 b and 142 b, or the grooves 132 c and142 c respectively formed in the first circuit board 132 and the secondcircuit board 142 may be disposed such that they do not overlap circuitpatterns printed on the boards, in order to prevent the circuit patternsfrom being cut off. Furthermore, the hook 167 corresponding to eachlocking hole 132 a and 142 a may comprise a plurality of hooks 167 thatare provided on each of the upper and lower ends of the reflector 160 atpositions spaced apart from each other by a predetermined distance. Thecoupling piece 168 corresponding to each fastening hole 132 b and 142 bmay also comprise a plurality of coupling pieces 168 that are providedon each of the upper and lower ends of the reflector 160 at positionsspaced apart from each other by a predetermined distance.

The transparent cover 170 has a hollow structure that is open onopposite ends thereof. The open opposite ends, in detail, the lower andupper ends, of the transparent cover 170 are respectively coupled to thefirst heat sink 120 and the second heat sink 150, thus preventing thefirst and second light emitting units 130 and 140 and the reflector 160from being exposed to the outside. The transparent cover 170 istransparent, allowing light emitted from the first light emitting unit130 and the second light emitting unit 140 to radiate from the LED lamp100 to the outside. The transparent cover 170 may comprise a lightdiffusion cover that can diffuse light emitted from the first and secondlight emitting units 130 and 140 before the light travels out of the LEDlamp 100.

As described above, the LED lamp 100 according to an exemplaryembodiment of the present invention is configured such that the firstlight emitting unit 130 and the second light emitting unit 140 arerespectively disposed below and above the reflector 160 that has apredetermined length. The first LED 134 of the first light emitting unit130 and the second LED 144 of the second light emitting unit 140 faceeach other so that light emitted from the first LED 134 and lightemitted from the second LED 144 respectively travel upwards anddownwards, that is, in the opposite directions. Further, the reflector160 is disposed between the first light emitting unit 130 and the secondlight emitting unit 140 so that light can also travel sideways from theLED lamp 100. Therefore, the LED lamp 100 according to an exemplaryembodiment of the present invention can overcome the limitations of LEDsthat emit light in only a forward direction, and can radiate light notonly forwards and rearwards but also sideways, thus forming the lightdistribution pattern in which light is emitted from the LED lamp 100 inall directions, in other words, forming the light distribution patternsimilar to that of conventional filament lamps.

Furthermore, the LED lamp 100 is provided with the first heat sink 120and the second heat sink 150 so that heat generated from the first lightemitting unit 130 and heat generated from the second light emitting unit140 can be independently dissipated, and the heat dissipation area canbe increased. Thereby, the present invention may use not only a lowpower LED but also a high power LED as each light emitting source, thusmaking it possible for the LED lamp 100 to emit a sufficiently intensityof light for applications previously limited to only conventionalfilament lamps.

Although the exemplary embodiments of the present invention have beendisclosed for illustrative purposes, the present invention is notlimited to such a specific structure, and those skilled in the art willappreciate that various modifications, additions and substitutions arepossible, without departing from the scope and spirit of the inventionas disclosed in the accompanying claims and their equivalents.

In addition, although the terms first, second, etc. have been usedherein, these should be understood as being used only to describedifferent elements. In other words, the above terms are used only fordistinguishing an element from another one. For instance, a firstelement may be named a second element while the second element may benamed a first element, if it does not depart from the scope and spiritof the present invention.

1. A light-emitting diode (LED) lamp, comprising: a base unit comprisinga connection part arranged at a first end thereof, the connection partconfigured to receive external power; a first light-emitting unitcomprising a first circuit board arranged on a second end of the baseunit, and at least one first LED mounted on the first circuit board; asecond light-emitting unit comprising a second circuit board spacedapart from the first circuit board, and at least one second LED mountedon the second circuit board, the second LED facing the first LED; areflector arranged between the first circuit board and the secondcircuit board, the reflector configured to reflect light emitted fromthe first LED and the second LED; and a transparent cover surroundingthe first light-emitting unit, the second light-emitting unit, and thereflector, wherein the transparent cover is configured to protect thefirst light-emitting unit, the second light-emitting unit, and thereflector from exposure to an outside environment.
 2. The LED lamp ofclaim 1, further comprising: a first heat sink arranged on the baseunit, the first heat sink comprising a mounting surface on which thefirst circuit board is mounted; and a second heat sink arranged on anend of the transparent cover, the second heat sink comprising a mountingsurface on which the second circuit board is mounted, wherein the firstheat sink is spaced apart from the second heat sink, and wherein thefirst heat sink and the second heat sink are configured to individuallydissipate heat generated from the first light-emitting unit and thesecond light-emitting unit, respectively.
 3. The LED lamp of claim 2,wherein at least one heat dissipation fin protrudes outwards from acircumferential surface of each of the first heat sink and the secondheat sink.
 4. The LED lamp of claim 1, wherein the reflector comprises:a first reflective part comprising a first reflective surface configuredto reflect light emitted from the first LED towards the transparentcover; and a second reflective part comprising a second reflectivesurface configured to reflect light emitted from the second LED towardsthe transparent cover.
 5. The LED lamp of claim 4, wherein the firstreflective part and the second reflective part are symmetrical to eachother based on a lateral line.
 6. The LED lamp of claim 5, wherein thefirst reflective surface comprises a linear longitudinal cross-sectionalshape that is inclined at an angle from a first end thereof to a secondend towards the transparent cover.
 7. The LED lamp of claim 5, whereinthe first reflective surface comprises a curved longitudinalcross-sectional shape that is curved from a first end thereof to asecond end towards the transparent cover.
 8. The LED lamp of claim 5,wherein the first reflective surface comprises: an inclined portioncomprising a longitudinal cross-sectional shape that is inclined at anangle from a first end thereof to a second end towards the transparentcover; and a vertical portion extending from the second end of theinclined portion.
 9. The LED lamp of claim 5, wherein the firstreflective surface comprises: a curved portion comprising a longitudinalcross-sectional shape that is curved from a first end thereof to asecond end towards the transparent cover; and a vertical portionextending from the second end of the curved portion.
 10. The LED lamp ofclaim 4, wherein the height of the longitudinal cross-sectional shape ofthe first reflective part is different from the height of thelongitudinal cross-sectional shape of the second reflective part. 11.The LED lamp of claim 10, wherein the first reflective surface comprisesa linear longitudinal cross-sectional shape that is inclined at an anglefrom a first end thereof to second end towards the transparent cover,and the second reflective surface comprises a linear longitudinalcross-sectional shape that is inclined at an angle from a first endthereof to second end towards the transparent cover.
 12. The LED lamp ofclaim 10, wherein the first reflective surface comprises a curvedlongitudinal cross-sectional shape that is curved from a first endthereof to second end towards the transparent cover, and the secondreflective surface comprises a linear longitudinal cross-sectional shapethat is inclined at an angle from a first end thereof to second endtowards the transparent cover.
 13. The LED lamp of claim 10, wherein thefirst reflective surface comprises a linear longitudinal cross-sectionalshape that is inclined at an angle from a first end thereof to secondend towards the transparent cover, and the second reflective surfacecomprises a curved longitudinal cross-sectional shape that is curvedfrom a first end thereof to second end towards the transparent cover.14. The LED lamp of claim 10, wherein the first reflective surfacecomprises a curved longitudinal cross-sectional shape that is curvedfrom a first end thereof to second end towards the transparent cover,and the second reflective surface comprises a curved longitudinalcross-sectional shape that is curved from a first end thereof to secondend towards the transparent cover.
 15. The LED lamp of claim 4, whereina first end of the first reflective part is connected to the firstcircuit board and a first end of the second reflective part is connectedto the second circuit board, and wherein the first reflective part andthe second reflective part are spaced apart from each other.
 16. The LEDlamp of claim 1, wherein a first end and a second end of the reflectorare respectively connected to the first circuit board and the secondcircuit board.
 17. The LED lamp of claim 16, wherein at least oneconnector member is arranged on each of the first end and the second endof the reflector, and the at least one connector members arerespectively connected to the first circuit board and the second circuitboard.
 18. The LED lamp of claim 16, wherein a coupling piece bent fromeach of the first end and the second end of the reflector in a firstdirection, wherein a coupling hole is arranged in the coupling piece,and a fastening hole is arranged in each of the first circuit board andthe second circuit board, and wherein the coupling piece is configuredto be fastened to the corresponding first circuit board or the secondcircuit board by tightening a fastening member into the coupling holeand the fastening hole.
 19. The LED lamp of claim 16, wherein the firstend and the second end of the reflector are respectively connected tothe first circuit board and the second circuit board by an adhesive. 20.The LED lamp of claim 17, wherein the at least one connector membercomprises a hook inserted into and locked to a corresponding lockinghole arranged in each of the first circuit board and the second circuitboard.
 21. A light-emitting diode (LED) lamp, comprising: a firstlight-emitting unit comprising at least one first LED; a secondlight-emitting unit comprising at least one second LED, the second LEDfacing the first LED; and a reflector arranged between the firstlight-emitting unit and the second light-emitting unit, the reflectorcomprising a first reflective surface and a second reflective surface.22. The LED lamp of claim 21, further comprising: a base unit comprisinga connection part arranged at a first end thereof, the connection partconfigured to receive external power; a first circuit board arranged ona second end of the base unit, the at least one first LED mounted on thefirst circuit board; a second circuit board spaced apart from the firstcircuit board, the at least one second LED mounted on the second circuitboard; and a transparent cover arranged around the first light-emittingunit, the second light-emitting unit, and the reflector, wherein thefirst reflective surface is configured to reflect light emitted from thefirst LED towards the transparent cover, and the second reflectivesurface is configured to reflect light emitted from the second LEDtowards the transparent cover.